In association with the operation of an engine, such as an engine that may be used to power an aircraft, the engine may generate or be associated with one or more streams. The streams may interact with one another, potentially on the basis of a state or position associated with of one or more valves. The valves may introduce a pressure loss in the engine, and such pressure loss has an impact on performance and efficiency. In particular, this pressure loss has an impact on the streams described above.